The ratio of the coefficient of linear expansions of two metals α1/α2 is 3.4 . If, when heated through the same temperature change , the ratio of the increase in lengths of the two metals , e1/e2 is 1.2, the ratio of the original length l1/l2 is

A bridge made of steel is 600 m long . What is the daily variation in its length if the night-time and day-time temperatures are 10°C and 35° respectively. The linear expansivity of steel is 0.000012°C-1

Which of the following statements clearly describe the behaviour of the fire alarm shown in Fig 8 below given that the linear expansivities of copper and steel are 2.0 x 10-5/°C and 1.2 x 10-5/°C respectively?

I. The bimetallic strip will not be able to close the circuit when there is fire.

II. The bimetallic strip will close the circuit when there is fire

III. If the copper and steel are interchanged, the circuit will close when there is fire.

The ratio of the linear expansivity of copper to that of iron is approximately 1.5. A specimen of iron and a specimen of copper expand by the same amount per unit rise in temprature . The ratio of their lengths is